Resist pattern formation method

Abstract

A method for forming a resist pattern, includes: forming a metal-containing resist film directly or indirectly on a substrate; laminating a protective film on the metal-containing resist film by applying a composition for forming a protective film; exposing to light the metal-containing resist film on which the protective film is laminated; and removing a portion of the exposed metal-containing resist film to form a pattern.

What is claimed is: 
     
         1 . A method for forming a resist pattern, comprising:
 forming a metal-containing resist film directly or indirectly on a substrate;   laminating a protective film on the metal-containing resist film by applying a composition for forming a protective film;   exposing to light the metal-containing resist film on which the protective film is laminated; and   removing a portion of the exposed metal-containing resist film to form a pattern.   
     
     
         2 . The method according to  claim 1 , wherein exposing comprises exposing to an extreme ultraviolet ray the metal-containing resist film on which the protective film is laminated. 
     
     
         3 . The method according to  claim 1 , wherein the composition for forming a protective film comprises a polymer comprising at least one structural unit selected from the group consisting of a structural unit represented by formula (1), a structural unit represented by formula (2), a structural unit represented by formula (3), and a structural unit represented by formula (4): 
       
         
           
           
               
               
           
         
         wherein in formulas (1) to (4), Rs are each independently a hydrogen atom, a halogen atom, a hydroxy group, or a monovalent organic group having 1 to 20 carbon atoms. 
       
     
     
         4 . The method according to  claim 1 , wherein removing the portion of the exposed metal-containing resist film comprises dissolving an exposed portion of the exposed metal-containing resist film with a developer to form a pattern. 
     
     
         5 . The method according to  claim 4 , wherein forming the metal-containing resist film comprises depositing a metal compound to form the metal-containing resist film. 
     
     
         6 . The method according to  claim 5 , wherein depositing the metal compound is performed by CVD or ALD. 
     
     
         7 . The method according to  claim 4 , wherein the metal-containing resist film comprises an organotin oxide. 
     
     
         8 . The method according to  claim 5 , wherein the metal compound comprises at least one selected from the group consisting of a haloalkyl Sn, an alkoxyalkyl Sn, and an amidoalkyl Sn. 
     
     
         9 . The method according to  claim 5 , wherein the metal compound comprises at least one selected from the group consisting of trimethyltin chloride, dimethyltin dichloride, methyltin trichloride, tris(dimethylamino)methyltin(IV), and (dimethylamino)trimethyltin(IV). 
     
     
         10 . The method according to  claim 4 , wherein the developer comprises alcohol. 
     
     
         11 . The method according to  claim 4 , wherein a temperature of the developer is 40° C. or higher. 
     
     
         12 . The method according to  claim 1 , wherein removing the portion of the exposed metal-containing resist film comprises removing an unexposed portion of the exposed metal-containing resist film by heating to form the pattern. 
     
     
         13 . The method according to  claim 12 , wherein a metal atom contained in the metal-containing resist film belongs to groups 3 to 16 of a periodic table. 
     
     
         14 . The method according to  claim 12 , wherein a metal atom contained in the metal-containing resist film is at least one selected from the group consisting of Sn and Hf. 
     
     
         15 . The method according to  claim 12 , wherein forming the metal-containing resist film comprises depositing a metal compound to form the metal-containing resist film. 
     
     
         16 . The method according to  claim 15 , wherein the metal compound is represented by formula (1):
   M(X) 4   (1)
   wherein in formula (1), M is Sn or Hf; and Xs are each independently a halogen atom or an alkyl group.   
     
     
         17 . The method according to  claim 15 , wherein the metal compound is at least one selected from the group consisting of Sn(CH 3 ) 4 , Sn(Br) 4 , and HfCl 4 . 
     
     
         18 . The method according to  claim 1 , wherein an unexposed portion of the exposed metal-containing resist film is volatilized to form the pattern.